ou should be ok to cut it, tips that i have heard are wrap some tape round the bar where its to be cut, this is supposed to give a nice clean cut, and stops the carbon from splintering,
use a saw guide for streight cut, if one isnt available, then improvise, ive heard of people using a lock on grip as a saw guide.
use a carbon specific saw blade. ( not sure if this is ture but i was told that there are specific blades for cutting carbon)
and defo wear some kind of mask, as i have also heard carbon dust can be very dangerouse,
good luck and happy cutting.

Yes you can cut some off (most that I have seen are actually marked for cutting).

The best method is a cutoff wheel for cutting metal. It doesn't leave any burrs and basically grinds through it and doesn't "saw" through it. I have a big 14" metal chopsaw that I use (I have it for cutting metal, not 5000 carbon handlebars ).

I would highly recommend NOT using any type of normal saw or bandsaw, and don't use a plumbing pipe cutter.

I've cut my handlebars with just a bench grinder, and just didn't breath in while doing it. You'll be fine.

Dear Arkon, thank you for taking the time to advise me. Please do not feel offended if I beg to differ, but no airway protection is most certainly not a good idea. That you feel OK on the next day does not mean much - this stuff can give cancer 20 yrs down the line (trust me, I know nothing about power tools but I am medical doctor by training). No breathing is better than inhaling, but some kind of mask is really necessary.

Nevertheless, I would intuitively believe that your method with the grinder may be best for this kind of material - if one can reliably control the sawdust.

I do not have a grinder - but I do have an electric Bosch saw. Do you believe that I can do the job with this tool?

hmm, If I were you, I wouldn't use that type of saw. I'm not an expert, but I would imagine you would have a much greater chance of marring the bars that way, and causing burs and so on.

If anything, I feel like a hack saw would work best if you don't have any access to a grinder. Worst come to worst, take it to a shop and pay the 5-10$. If they mess the bars up, they'll be held liable.

I do not have a grinder - but I do have an electric Bosch saw. Do you believe that I can do the job with this tool?

I have a similar jigsaw (it's a Bosch model in fact). Personally, I would NOT use that saw. I have cut PVC and metal pipe with it, and I feel if it catches in the cut and the saw starts jumping up and down you will ruin your handlebars.

If you do want to try it, I would use a tile-cutting jigsaw blade such as this type and be sure the handlebars are secured to a solid surface so they don't move:

I'm a machinist that works entirely in composites/carbon fiber, the best thing for you to use is a diamond saw....They make diamond saw cutters for Dremmel tools that work pretty well, just make sure you lightly sand the edges after to keep the material from de-laminating

There is no problem cutting carbon bars. I would wrap the bars with electrical tape, use a cutting guide(steerer tube cutting guide by Park Tools), and a hack saw. Sand down the bar after cutting to avoid getting carbon splinters and you're good to go.

OK, guys, I ended up doing it with a dremel and a small cutwheel. It was very easy. Actually it was embarassingly easy. If I had known that it would be so easy, I wouldn't have bothered everybody here in the Forum.

It took me literally 5 minutes. The cutwheel went through the carbon like butter. The cutwheel is made of some sandpaper-like stuff, so I used it to sand the edges in the same go.

Thanks to every poster for their helpful advice! Now let's just hope that the shorter bar is more comfortable for my body (I have yet to take it to the hills...).